getting ‘Already Installed’ page when activitating permalinks

Hey Guys,

I’m new to WordPress.
But i have quite some experience on debian/php/mysql/htaccess

My problem:

When i activate permalinks, let’s say ‘Date and name based’, and after a ctrl+f5 refresh, all the links on my WordPress website result in a WordPress error page:
(accept for one link, the page-link ‘over’. I think it is odd that this is the only working link..)

‘Already Installed’

You appear to have already installed WordPress. To reinstall please clear your old database tables first.

you can check it out @ https://wijnmaalen.mine.nu/wordpress/

This is my own server and before you are thinking that mod_rewrite isn’t properly installed. i can assure you that it is properly installed.
example: (Same server, site relys purely on mod_rewrite links)
https://wijnmaalen.mine.nu/websites/mijnsein.nl/

content htaccess file: ( generated by WordPress )

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /wordpress/
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /wordpress/index.php [L]
</IfModule>
# END WordPress

Without the permalinks activated WordPress works like a charm.

Since the htaccess is generated by WordPress i don’t know where the problem occurs.

Also Google isn’t much of a help because no one else seems to have similar problems.

Thanks in advance guys!